Open-air and underground collaborative mining method

Abstract

The invention belongs to the technical field of underground ore body mining, and discloses an open-air and underground collaborative mining method, which comprises the following steps of: dividing a stope according to the ore characteristics of each part in the stope, and specifying a mining scheme; dividing the large-volume ore blocks into small-volume ore bodies, and designing a mining process for the small-volume ore bodies; arranging a transportation system, a ventilation and drainage system and key facilities in the ore body according to the constraint of environmental conditions and the design of the mining process; carrying out open-air stoping; underground recovery is carried out; filling the underground goaf; then, returning to the open-air stoping work until the isolating layer pillars are recovered; a section ditch is formed above a filling body in an open-cast mining layer for propelling, open-cast blasting vibration is utilized for secondary recovery of well mining residual ore, and an isolating layer ore pillar is recovered. According to the method, the stable geological supporting force of the mining area is guaranteed, meanwhile, the isolation pillars are converted into resources capable of being completely recycled, and the ore recovery rate is increased.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of underground ore body mining, and particularly relates to a method for open-pit and underground collaborative mining. BACKGROUND

[0002] At present, many metal and non-metal mines begin to try to convert from underground mining to open-pit mining in order to expand production scale and improve economic benefits. The main mining mode is as follows: the ore body is divided into multiple ore belts, the near-surface ore belt is mined by open-pit mining, and the underground ore body stope is mined by using methods such as medium-length hole and filling. Usually, an isolation pillar is left between the open-pit mining area and the underground mining area, which is used to recover the isolation pillar by using methods such as medium-length hole blasting after the open-pit mining and underground mining are completed. However, the overall recovery rate of the ore body is relatively low when the above-mentioned mode is used for mining. In general, a certain proportion of isolation pillars is left between the open-pit mining area and the underground mining area as an isolation belt to enable the open-pit mining and the underground mining to be operated simultaneously. Most of the isolation pillars are permanently lost and cannot be recovered.

[0003] In summary, the defect existing in the prior art is that the isolation pillar exists as a permanent support body and cannot be mined. SUMMARY

[0004] In view of the problems existing in the prior art, the present application provides a method for open-pit and underground collaborative mining.

[0005] The present application is implemented as follows: a method for open-pit and underground collaborative mining comprises the following steps: Divide the stope according to the characteristics of each part of the ore in the stope, and specify the mining scheme; Divide the large-volume ore blocks into small-volume ore bodies, and design a mining process for the small-volume ore bodies; According to the constraints of the environmental conditions and the design of the mining process, arrange the internal transportation system, the ventilation and drainage system, and the key facilities of the ore body; Perform open-pit mining; wherein the open-pit mining direction is from the top of the ore body to the bottom of the ore body; Perform underground mining; wherein the underground mining direction is from the bottom of the ore body to the top of the ore body; Fill the underground goaf; determine whether the mining work of the open-pit mining layer is performed to approach the horizontal plane of the underground mining layer; thereafter, return to perform the open-pit mining work until the mining work of the open-pit mining layer is performed to approach the horizontal plane of the underground mining layer, and the isolation layer pillar is recovered; Sectionalize and advance the open-pit mining layer above the filling body, use open-pit blasting vibration to recover the residual ore in the well, and recover the isolation layer pillar.

[0006] Further, before performing the open-pit mining, the method further comprises: Perform preliminary underground mining to form a preliminary goaf; sending the waste rock generated by flattening the open-pit mining area or mining the open-pit mining area into the preliminary goaf generated after the underground mining through the draw shaft; using the waste rock in the open-pit mining area as aggregate, combining with the high-fluidity filling material to forcibly fill the preliminary goaf, so that the filling body is in seamless contact with the roof, and the support strength equivalent to the original pillar is formed; after the underground recovery, further comprising: sending the waste rock generated by flattening the open-pit mining area or mining the open-pit mining area into the goaf generated after the underground mining through the draw shaft; Correspondingly, in the filling of the underground goaf, further comprising: after each sublevel recovery of the underground mining layer, using the waste rock in the open-pit mining area as aggregate, combining with the high-fluidity filling material to forcibly fill the goaf, so that the filling body is in seamless contact with the roof, and the support strength equivalent to the original pillar is formed.

[0007] Further, when the underground recovery is performed, further comprising: synchronously pausing the open-pit mining; When the underground goaf is filled, further comprising: synchronously performing the open-pit recovery work.

[0008] Further, after the filling of the underground goaf is completed, further comprising: During the maintenance of the filling layer of the underground goaf, the open-pit blasting mining continues to advance.

[0009] Further, after the open-pit recovery work is performed, until the mining work of the open-pit mining layer is performed to the recovery isolation layer pillar before the mining work of the open-pit mining layer is performed to the recovery isolation layer pillar, further comprising: According to the mechanical model, the safety strength requirement force of the filling body is calculated, and the blasting safety distance is obtained according to the safety strength requirement force; when the horizontal distance between the open-pit mining and the underground mining work face approaches the blasting safety distance, the open-pit mining is paused, and after the strength of the filling body of the underground mining area reaches the safety strength requirement force, the open-pit mining work is continued to advance.

[0010] Further, in the division of the mining area according to the characteristics of each part of the ore in the mining area and the provision of the mining and excavation scheme, comprising: According to the geological conditions, the ore and rock in the open-pit mining area are divided into surrounding loose ore and rock of the collapse area, loose body ore and rock of the collapse area, peripheral ore and rock of the collapse area, and surrounding rock of the goaf.

[0011] Further, after the ore and rock in the open-pit mining area are divided into surrounding loose ore and rock of the collapse area, loose body ore and rock of the collapse area, peripheral ore and rock of the collapse area, and surrounding rock of the goaf according to the geological conditions, further comprising: from top to bottom, the surrounding loose ore and rock of the collapse area, the loose body ore and rock of the collapse area, and the surrounding rock of the goaf are gradually stripped off in layers and gradually sloped; The peripheral ore and rock of the steep slope stripping collapse area are stripped from top to bottom, and the operation face is advanced along the ore body trend.

[0012] Further, in the division of the stope according to the characteristics of the ore in each part of the stope, and the provision of the mining scheme, comprising: According to the geological conditions, the ore and rock in the open pit are divided into loose ore and rock around the collapse area, loose body ore in the collapse area, peripheral ore and rock of the collapse area, and surrounding rock of the mined-out area; After arranging the internal transportation system, ventilation and drainage system and key facilities of the ore body according to the constraints of environmental conditions and the design of mining process, further comprising: The pillar in the collapse area is recovered by caving method; the top pillar resources in the collapse area are mainly recovered by large-diameter deep hole pressure top and section recovery, the inter-column and bottom column are mainly recovered by sublevel caving method without bottom column, and the ore body is mainly recovered by stage open stope and subsequent filling method.

[0013] Further, in the underground mining, further comprising: The sublevel millisecond blasting and double pre-splitting blasting technology of detonating cord + detonating cable is adopted, the middle hole is designed to be initiated first and the side row hole is initiated later in single row blasting, the maximum single response explosive quantity is controlled, and the influence of blasting on the surrounding is strictly limited; Transporting the ore body after blasting.

[0014] Further, in the underground mining, before transporting the ore body after blasting, further comprising: According to the dynamic support design of the roof in the underground stope disturbed by open blasting mining, the overall instability caused by the continuously enhanced blasting disturbance is avoided.

[0015] In summary, the technical effects that can be achieved by the present application are: after each sublevel of the underground mining layer is mined, high flowability filling material is immediately used for forced filling to ensure that the filling body is dense and seamlessly contacts the roof, thereby quickly forming an artificial filling body equivalent to the original rock pillar support strength, and the open pit mining layer can be safely advanced to the bottom slope direction for sectioning and stripping and blasting operation; At the same time, the strong vibration generated by large-scale blasting in the process of open pit mining is used to cooperatively control the advancing direction and the rigid support of the filling body, and the two parts of resources are planned to be broken and recovered again: one is the ore remaining in the roof or side slope area during underground mining (such as incomplete residual ore); the other is the pillar resource itself in the most isolated layer, so as to ensure the stability of the geological support of the mining area while converting the isolated pillar into completely recoverable resources, and significantly improving the overall recovery rate of the ore.

[0016] The above description is only a summary of the technical solutions of the present application. In order to enable the technical means of the present application to be more clearly understood, and to be implemented according to the content of the description, and in order to enable the above and other purposes, characteristics and advantages of the present application to be more apparent and easy to understand, the following specific embodiments of the present application are described. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is a basic flowchart of a surface and underground collaborative mining method provided in an embodiment of the present application; Figure 2 is a first optimization flowchart of a surface and underground collaborative mining method provided in an embodiment of the present application; Figure 3 is an optimization flowchart of a surface and underground collaborative mining method provided in an embodiment of the present application, regarding waste rock treatment; Figure 4 is an optimization flowchart of a surface and underground collaborative mining method provided in an embodiment of the present application, regarding surface-underground collaborative working time staggering; Figure 5 is an optimization flowchart of a surface and underground collaborative mining method provided in an embodiment of the present application, regarding process optimization during filling layer maintenance; Figure 6 is an optimization flowchart of a surface and underground collaborative mining method provided in an embodiment of the present application, regarding surface-underground collaborative working safety requirements; Figure 7 is an optimization flowchart of a surface and underground collaborative mining method provided in an embodiment of the present application, regarding stope geological condition division; Figure 8 is an optimization flowchart of a surface and underground collaborative mining method provided in an embodiment of the present application, regarding differential stope stripping construction; Figure 9 is an optimization flowchart of a surface and underground collaborative mining method provided in an embodiment of the present application, regarding differential stope pre-underground mining; Figure 10 is an optimization flowchart of a surface and underground collaborative mining method provided in an embodiment of the present application, regarding surface-underground collaborative underground stope roof reinforcement support; DETAILED DESCRIPTION

[0018] The embodiments of the technical solutions of the present application will be described in detail below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present application, and therefore only serve as examples, and cannot limit the protection scope of the present application.

[0019] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of this application; the use of the terms "including," "comprising," or "having" and variations thereof herein is intended to be broad and encompass the terms "consisting of" and "consisting essentially of" and variations thereof. Unless otherwise required by context, singular terms shall include pluralities and vice versa. Unless otherwise required by context, the use herein of the singular is also to be construed as a use of the plural and vice versa.

[0020] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise explicitly and specifically limited.

[0021] Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearance of the phrase in various places in the specification is not necessarily all referring to the same embodiment, or to a particular embodiment, or to a particular set of embodiments, and is not necessarily used consistently throughout. It will be explicitly understood by one of ordinary skill in the art that the embodiments described herein can be combined with other embodiments.

[0022] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B, which can represent the three cases of A existing alone, A and B existing together, and B existing alone. In addition, the character " / " in this paper generally represents that the front and rear associated objects are a "or" relationship.

[0023] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two), and similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0024] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and therefore cannot be understood as limiting the embodiments of the present application, which do not indicate or imply that the indicated devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the embodiments of the present application.

[0025] In the description of the embodiments of the present application, unless otherwise explicitly specified and limited, the technical terms "mounting", "connection", "linking", "fixing" and the like should be understood in a broad sense, for example, can be fixed connection, can also be detachable connection, or integral; can be mechanical connection, can also be electrical connection; can be direct connection, can also be indirect connection through an intermediate medium, can be internal communication of two elements or interaction relationship between two elements. For those skilled in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0026] In order to make the purpose, technical scheme and advantages of the present application more clear, the present application will be further described in detail below in combination with embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and not to limit the present application.

[0027] In order to make the purpose, technical scheme and advantages of the present application more clear, the present application will be further described in detail below in combination with embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and not to limit the present application.

[0028] Reference Figure 1 A surface and underground collaborative mining method, comprising the following steps: S101, dividing the stope according to the characteristics of each part of the ore, and stipulating the mining scheme; S102, dividing the large bulk ore into small bulk ore, and designing the mining process for the small bulk ore; S103, arranging the internal transportation system, ventilation and drainage system and key facilities in the ore body according to the constraints of environmental conditions and the design of the mining process; S104, conducting surface mining; wherein the surface mining direction is from the top of the ore body to the bottom of the ore body; S105, conducting underground mining; wherein the underground mining direction is from the bottom of the ore body to the top of the ore body; S106, filling the underground goaf; S10600, judging whether the mining work of the surface mining layer is conducted to approach the horizontal plane of the underground mining layer; thereafter returning to conduct the surface mining work until the mining work of the surface mining layer is conducted to approach the horizontal plane of the underground mining layer to recover the isolation layer pillar; S107, opening a section trench above the filling body in the surface mining layer, recovering the residual ore in the well by using the surface blasting vibration, and recovering the isolation layer pillar.

[0029] Firstly, the stope structure is divided, that is, according to the rock mechanics characteristics of each part in the stope, the difference of ore grade distribution is scientifically divided to identify the mining suitability and constraint conditions of different regions, and to ensure that the subsequent open pit and underground mining range can be efficiently divided and safely cooperated; Then, the ore block is divided, and the large volume ore block is divided into small pieces. Based on structural mechanics and mining engineering, by reducing the size of single stoping, the ground pressure appearance risk is reduced, and the controllability and flexibility of the stoping process are improved. Then, the mining and cutting engineering is arranged. According to the occurrence conditions of the ore body, environmental constraints (such as surface protection, slope stability) and the foregoing fine mining process design, the internal transportation system, ventilation and drainage system and key facilities of the ore body are arranged to optimize the engineering layout, meet the safe and efficient operation requirements under specific environmental constraints, and create a smooth and safe internal and external working environment for open pit and underground cooperative operation. In the process of open pit and underground cooperative mining, the open pit mining is pushed forward from the top, while the underground mining is pushed forward from the bottom. The two form an upward and downward reverse advancing mining space in space, and are vertically staggered. By taking advantage of the low construction difficulty of open pit overburden stripping and the flexible advantage of underground mining not depending on the storage form of ore body, the production interference between the two is effectively avoided, and conditions are created for subsequent underground filling and upper residual recovery, which naturally reduces the mutual disturbance of upward and downward mining. When each sublevel of underground mining is mined, high mobility filling material is immediately used for forced filling to ensure that the filling body is dense and seamlessly connected to the top. The rapid setting high strength filling body actively provides artificial support to quickly form a support body with mechanical support strength equivalent to the original rock pillar, thereby effectively controlling rock movement and supporting the overlying rock strata. As a result, the isolation zone pillar can be mined on a large scale, and the open pit mining layer can be safely pushed forward and blasted under the protection of the stable artificial filling body above. At the same time, by using the vibration energy generated by large-scale blasting in open pit mining, combined with the designed advancing direction and the high strength support of the filling body, the roof or corner residual ore produced during underground mining and the originally planned permanent isolation pillar can be safely and efficiently broken and recycled. The key beneficial effect of this link is to significantly improve the overall recovery rate of ore, especially the successful recovery of a large amount of isolation pillar resources that must be abandoned due to permanent support function in the prior art.

[0030] Reference Figure 2 Further, before S104, open pit mining, also includes: S1005, preliminary underground mining is performed to form a preliminary mined-out area; S1006, waste rock generated by leveling the open pit mine or mining the open pit mine is transported to the preliminary mined-out area generated after underground mining through a draw shaft; S1007, using the waste rock in the open pit area as aggregate, combined with high fluidity filling material to forcibly fill the preliminary goaf, so that the filling body is in seamless contact with the roof, forming a support strength equivalent to the original pillar; After S105, underground mining, further comprising: S10051, the waste rock generated by the open pit mining is transported into the goaf generated after the underground mining through the draw shaft; Correspondingly, in S106, filling the underground goaf, further comprising: S1061, after each sublevel mining of the underground mining layer, using the waste rock in the open pit area as aggregate, combined with high fluidity filling material to forcibly fill the goaf, so that the filling body is in seamless contact with the roof, forming a support strength equivalent to the original pillar.

[0031] When the open pit mining advances from the top to the bottom, the waste rock generated by stripping is retained and backfilled into the goaf formed by underground mining, using the open pit stripping waste rock as the filling material of the underground goaf, realizing the on-site recycling of waste rock, avoiding waste rock discharge and cost increase, and at the same time providing immediate support for the underground goaf. The open pit mining strips the overburden layer from top to bottom, and the underground mining mines the ore from bottom to top, forming an inverse advancing working face in the vertical direction, so that the waste rock can be filled into the underground goaf nearby without long-distance transportation; After the underground goaf is filled with waste rock, the waste rock is compacted or supplemented with cement grouting to form an artificial filling body with certain bearing capacity, and the mechanical support function of the isolation pillar is replaced by the artificial filling body, so that the isolation pillar is changed from a "permanent support structure" to a "recoverable resource", and the isolation pillar does not need to be permanently set, and can be recovered with the residual ore; In addition, the artificial filling body not only supports the overburden, but also provides a rigid reaction surface for open pit blasting vibration, ensuring efficient transmission of vibration energy to the target ore body, and efficiently recycling the rock vibration generated by open pit blasting to clean the residual ore.

[0032] Reference Figure 3 Further, in the open pit and underground collaborative mining, further comprising: S105, when performing underground mining, further comprising: S1051, synchronously suspending open pit mining; When filling the underground goaf in S106, further comprising: S1062, synchronously performing open pit mining.

[0033] In the process of open-pit and underground collaborative mining, first, underground blasting mining is performed, at which time open-pit mining operations need to be suspended, and by staggering the blasting time sequence of the open-pit and the underground, the direct safety risks faced by the open-pit large equipment and personnel due to the vibration, flying stones or shock waves generated by the underground blasting are avoided, and at the same time, the initiation precision of the open-pit operation and the ore falling effect of the underground blasting are avoided; after the underground blasting is completed, the underground goaf filling work is immediately started, and the waste rock generated by the previous open-pit leveling or mining is used to backfill the goaf, and high fluidity filling material is used to fill to the dense top contact state, and after the filling body rapidly hardens, an artificial support body equivalent to the original ore rock is formed, which on the one hand provides a stable base condition for subsequent open-pit operations, and on the other hand actively replaces the isolation pillar function, so that it is changed from a permanent support structure to a recyclable resource. The alternating suspension and start of open-pit and underground operations is based on the rock mass mechanical response period (such as blasting vibration attenuation, filling body strength growth) to dynamically adjust the production rhythm, which not only ensures the safety of personnel and equipment, but also solves the technical problem of the isolation pillar that cannot be mined through the filling replacement and blasting coordination mechanism.

[0034] Referring to Figure 4 Further, after S106, filling the underground goaf is completed, and further comprising: S1063, during the curing period of the filling layer in the underground goaf, open-pit blasting mining continues to advance.

[0035] After the underground goaf is filled with high fluidity filling material, the filling body enters the curing period, and the hydration reaction of the filling material (such as full tailings mixed with cementing material) needs to be formed under static conditions to form a support strength equivalent to the original ore pillar, so as to provide a stable foundation for the upper open-pit operation; Therefore, during this period, in the open-pit blasting mining work, the blasting parameters (such as hole diameter, hole depth, charge amount) and the advancing direction need to be accurately controlled to continue open-pit mining outside the safe distance above the filling body, and use the time window of the curing period of the filling body to ensure that open-pit mining and filling body strength development are staggered in space and time, so as to avoid the disturbance and damage of blasting vibration to the unconsolidated filling body, and at the same time maintain the continuity of mine production capacity.

[0036] The key of this process is that the strength development of the curing period filling body needs a static environment, and the vibration energy generated by the open-pit blasting operation decays exponentially with distance, and by designing the horizontal stagger distance (such as ≥20 meters) of the open-pit advancing line and the filling area, the blasting vibration is attenuated to below the safety threshold (usually the particle vibration velocity <5 cm / s) when it propagates to the filling body, so that the open-pit operation has approximately no disturbance effect on the curing period of the filling body before the filling body reaches the designed strength, so as to avoid affecting the cementation quality.

[0037] Referring to Figure 5Further, before the recovery of the isolated layer pillar, further comprising: S1064, calculating the safety strength requirement force of the filling body according to the mechanical model, and obtaining the blasting safety distance according to the safety strength requirement force; when the horizontal distance between the open-pit mining and the underground mining working face approaches the blasting safety distance, the open-pit mining is suspended, and the open-pit mining is continued after the strength of the filling body in the mine area reaches the safety strength requirement force.

[0038] In the process of open-pit and underground collaborative mining, first, the safety strength requirement force of the filling body is calculated according to the mechanical model, the dynamic response characteristics of the filling body under the action of blasting load are analyzed through rock mechanics theory (such as RHT model or Sadovskiy blasting vibration attenuation formula), and the minimum strength threshold required by the filling body to resist blasting disturbance is quantitatively determined combined with the filling body material parameters (such as cementation strength, density) and the blasting vibration propagation law (such as the exponential relationship between vibration speed and charge quantity, distance), to provide accurate scientific basis for subsequent safety distance control and avoid the risk of filling body failure caused by empirical design; Then, the blasting safety distance is calculated based on the strength threshold, the theoretical model parameters are dynamically corrected according to the blasting vibration attenuation formula and the regression analysis of the field vibration monitoring data, so as to accurately determine the critical space range in which the open-pit blasting operation does not damage the underground filling body.

[0039] In actual collaborative operation, the horizontal distance between the open-pit mining and the underground mining working face is monitored in real time, and when the monitoring shows that the distance approaches (or equals) the previously calculated blasting safety distance, the system immediately suspends the open-pit mining to avoid the transmission of vibration energy to the filling body that does not reach the strength threshold, thereby further avoiding the structural damage of the filling body due to insufficient strength under blasting vibration, and ensuring that it can stably replace the supporting function of the traditional isolated pillar; During the suspension period, the filling layer in the underground goaf enters the strength maintenance period, and the cementing material continuously hydrates to improve the strength of the filling body. During this period, non-destructive testing methods (such as ultrasonic wave or penetration instrument) are used to verify whether the actual strength of the filling body meets the safety strength requirement force required by the mechanical model. After the strength of the filling body is confirmed to meet the standard, the open-pit mining is resumed, and at this time the open-pit blasting can be safely carried out under the rigid support protection provided by the filling body to recover the isolated layer pillar.

[0040] In summary, through the above control process, the stability of the filling body under blasting disturbance is ensured, so that it can replace the permanent supporting effect of the isolated pillar, thereby ensuring the safety of the recovery work of the isolated pillar.

[0041] Referring to Figure 6Further, in S101, the mining area is divided according to the characteristics of each part of the ore in the mining area, and a mining scheme is specified, including: S1011, according to the geological conditions, the ore rock in the open pit is divided into surrounding loose ore rock of collapse area, loose body ore rock of collapse area, peripheral ore rock of collapse area and surrounding rock mass of mined-out area.

[0042] The workflow starts with geological exploration and rock mass mechanics analysis. Through geological structure (such as fault, joint development degree), rock mass integrity coefficient and stress distribution state, the ore rock is divided into four types of regions: Surrounding loose ore rock of collapse area, characterized by fracture development and decreased bearing capacity; Loose body ore rock of collapse area, characterized by complete loss of original structure and granular state; Peripheral ore rock of collapse area, characterized by being in the elastic deformation stage and relatively complete rock mass; Surrounding rock mass of mined-out area, characterized by stress concentration due to mining influence.

[0043] Through the above zoning method, different management can be implemented for rock masses with different stability to avoid resource waste or safety accidents caused by unified mining.

[0044] For surrounding loose ore rock of collapse area, low disturbance blasting technology can be used to control blasting vibration speed and prevent secondary collapse, thereby recovering boundary residual ore that cannot be safely mined by traditional methods, while avoiding damage to the structure of adjacent filling bodies; For loose body ore rock of collapse area, mechanical shoveling can be directly used. This type of ore rock has no cementing force, and mechanical shoveling can efficiently strip, significantly reduce ore dilution and avoid blasting dust pollution. After mechanical recovery, the loose body ore rock can be used as aggregate for filling bodies, realizing waste rock recycling; In the peripheral ore rock area of the collapse area, conventional bench mining is implemented. The peripheral rock mass is in the elastic deformation zone, and conventional blasting will not cause chain instability, thereby maintaining the stability of the main production capacity of the mine and providing a safety barrier for the inner high-risk area. Therefore, mining in this area can be carried out during the maintenance period of the filling body in the mined-out area; For surrounding rock mass of mined-out area, the workflow simultaneously implements anchor rod + metal mesh support. The support strength of the surrounding rock mass of the mined-out area cooperates with the filling body to form a composite support system, inhibits the rock mass tension and cracking in the stress concentration area, avoids local collapse induced by large-area landslides, and ensures the safety of open pit and underground collaborative operation.

[0045] Reference Figure 7 Further, after S1011, according to the geological conditions, the ore rock in the open pit is divided into surrounding loose ore rock of collapse area, loose body ore rock of collapse area, peripheral ore rock of collapse area and surrounding rock mass of mined-out area, it further includes: S10111, layer by layer from top to bottom, gradually stripping the loose ore rock around the collapse area, loose body ore rock in the collapse area, and the rock mass around the goaf; S10112, stripping the ore rock around the collapse area from top to bottom, and advancing the working face along the strike of the ore body.

[0046] For the loose ore rock around the collapse area, loose body ore rock in the collapse area, and the rock mass around the goaf, the working process adopts layer by layer from top to bottom, gradually stripping the slope. By reducing the single stripping thickness (each layer ≤5m) and controlling the stripping slope, combined with mechanical shovel loading or low disturbance blasting, the internal stress of the rock mass is gradually released and the exposed range of the free surface is reduced, thereby inhibiting crack propagation and secondary collapse, ensuring the safety of operation in high-risk areas; For the ore rock around the collapse area, the working process adopts layer by layer from top to bottom, steep slope stripping, relying on the high integrity of the rock mass, and advancing the working face in the form of combined steps along the strike of the ore body. By reducing the amount of stripping with steep slope structure and improving efficiency with continuous equipment operation, the production stripping ratio is significantly reduced, the stability of the main capacity of the open pit is maintained, and a safe buffer space is provided for the stripping of the inner high-risk area.

[0047] Layered gentle slope stripping provides safe operating conditions for mechanical shovel loading of loose body ore rock in the collapse area, and the waste rock stripped can be directly used as filling aggregate for underground goaf, realizing waste rock recycling; the along-strike advancing mode of step steep slope stripping is coordinated with the design of blasting parameters in the quantification of safety distance, ensuring that the peripheral stripping does not affect the development of the inner filling body strength.

[0048] Reference Figure 8 Further, in S101, the stope is divided according to the characteristics of each part of the ore, and the mining plan is specified, including: S1011, according to the geological conditions, the ore rock in the open pit is divided into loose ore rock around the collapse area, loose body ore rock in the collapse area, ore rock around the collapse area, and rock mass around the goaf; After the design of the mining process and the constraints of the environmental conditions, the internal transportation system, ventilation and drainage system, and key facilities of the ore body are arranged, further including: S1012, using caving method to recover the ore pillar in the collapse area; the top pillar resources in the collapse area are mainly recovered by large-diameter deep hole pressure top and section recovery, the interval column and the bottom column are mainly recovered by bottomless section caving method, and the ore body is mainly recovered by stage open stope and subsequent filling method.

[0049] For the top pillar resources in the collapse area, large-diameter deep hole pressure top and section recovery is adopted, which uses large-diameter deep hole to blast from the top of the top pillar to the bottom in sections, increases the single blasting height to 10-15 meters by sectioning, and thus efficiently recovers the top pillar residual ore; The pillar and the bottom pillar are recovered by the bottomless sublevel caving method, fan-shaped deep holes are drilled in the sublevel roadway, and the ore is recovered after blasting under the caving overburden, without reserving the bottom structure, so as to eliminate the loss of the bottom pillar and realize the full recovery of the pillar and the bottom pillar resources; The main part of the ore body is recovered by the stage empty field and subsequent filling method, the ore room is first mined by the empty field method, and the goaf is immediately filled with waste rock aggregate after mining to form an artificial support body to replace the original ore pillar, thereby providing stable support conditions for subsequent open pit steep slope stripping, and realizing the recycling of waste rock.

[0050] Reference Figure 9 Further, in S105, the underground mining further comprises: S1052, using lead blasting tube + lead blasting cable segmented millisecond blasting and double pre-splitting blasting technology, when single row blasting, the middle hole is designed to be initiated first, and the side row hole is initiated later, the maximum single response explosive quantity is controlled, and the influence of blasting on the surrounding is strictly limited; S1053, transporting the ore body after blasting.

[0051] The middle hole in the row is first initiated by the lead blasting tube, which breaks the core area of the ore rock through stress wave superposition effect, thereby creating a new free surface for the side row hole, reducing the subsequent blasting clamping effect, and improving the uniformity of ore crushing; The side row hole is initiated according to the designed order 25-50 milliseconds after the middle hole is initiated, and the secondary crushing is realized by using rock collision effect, thereby reducing the large block rate and reducing the crushing cost.

[0052] According to the vibration safety threshold, the single segment explosive quantity is dynamically allocated, and the total explosive quantity is dispersed to multiple segments by the lead blasting tube segment design, so as to reduce the blasting vibration speed, reduce the damage of the underground filling body structure, and ensure the stable operation of the open pit equipment.

[0053] Reference Figure 10 Further, in S105, the underground mining further comprises: S10511, according to the dynamic support design of the roof in the underground stope caused by the open pit blasting mining blasting disturbance, to avoid the overall instability caused by the continuously enhanced blasting disturbance.

[0054] By real-time monitoring of the vibration speed, frequency and stress wave propagation direction generated by open pit blasting, combined with geological radar and three-dimensional laser scanning data, the cumulative damage effect of blasting disturbance on the roof of the underground stope is analyzed, and the support risk level is dynamically divided according to the rock mass integrity coefficient and stress concentration degree, so as to accurately identify the high-risk area of roof instability, provide data support for dynamic support design, and avoid resource waste or insufficient support caused by unified support.

[0055] Then, a differential support design is implemented: High-risk area: such as goaf surrounding rock mass, fracture development area adopts anchor cable truss combined support system, through high prestressed steel strand into the stable rock layer, truss anchor cable is anchored in the deep surrounding rock of roadway two shoulder nest extrusion area, forms the upward counter moment to offset the horizontal stress, and cooperates with foam concrete shotcrete to seal the surface layer crack, so as to inhibit the off bedding and caving induced by blasting vibration, and inhibit the roof subsidence.

[0056] Low-risk area: such as collapse area surrounding intact rock mass adopts high pre-tightening force anchor rod + metal net support, high initial pre-tightening force is applied, the continuous bearing structure is formed by the combined action of anchor rod and metal net, the shear strength of shallow rock mass is improved, so as to control the local rock block off and reduce the support cost.

[0057] In the support construction, grouting reinforcement and dynamic adjustment are carried out simultaneously, water is sprayed in the roof or fracture zone, grouting is carried out to the fissure through the self-drilling anchor rod, the off bedding space in the rock mass is filled, and after grouting curing, the I-beam is installed to the anchor rod for secondary reinforcement, so as to restore the cementing strength of rock mass and improve the anti-blasting vibration capacity of support structure.

[0058] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto, any modification, equivalent replacement and improvement within the technical range disclosed by the present application, which is made by any skilled person in the art within the spirit and principle of the present application, should be covered within the protection scope of the present application.

[0059] It should be noted that the present application is not limited to the above-mentioned embodiments. The above-mentioned embodiments are only examples, and embodiments having the same technical idea and playing the same role and effect within the technical solution range of the present application are all included in the technical range of the present application. In addition, within the scope of the main idea of the present application, various modifications, combinations of part of the components in the embodiments to construct other ways which can be thought by those skilled in the art are also included in the scope of the present application.

Claims

1. A method for co-existing open-pit and underground mining, characterized in that, Includes the following steps: The mining area is divided according to the characteristics of the ore in each part of the mining area, and the mining plan is specified; Large-volume ore blocks are divided into smaller-volume ore bodies, and mining processes are designed for the smaller-volume ore bodies. Based on environmental constraints and the design of the mining process, the internal transportation system, ventilation and drainage system, and other key facilities of the ore body are arranged. Open-pit mining shall be carried out; wherein, the direction of open-pit mining is from the top side of the ore body to the bottom side of the ore body; Underground mining shall be carried out; wherein, the direction of underground mining is from the bottom side of the ore body to the top side of the ore body. Fill the underground goaf; determine whether the mining work of the open-pit mine has progressed to near the level of the underground mine; then return to the above-mentioned open-pit mining work until the mining work of the open-pit mine has progressed to near the level of the underground mine, at which point the isolation layer pillar is recovered; In open-pit mining, trenches are dug above the backfill to advance the mine, and residual ore is recovered through open-pit blasting vibrations. The isolation layer pillars are also recovered.

2. The method for combined open-pit and underground mining according to claim 1, characterized in that, Prior to the open-pit mining, the following is also included: Preliminary underground mining was carried out to form a preliminary goaf. Waste rock generated from leveling or mining open-pit mines is transported via ore passes to the initial goaf area created after underground mining. Using waste rock from open-pit mines as aggregate, combined with high-flowability filling material, the initial goaf is forcibly filled, so that the filling body is in seamless contact with the roof, forming a support strength equivalent to the original pillar. Following the underground mining operation, the following is also included: Waste rock generated from open-pit mining is transported via ore passes to the goaf area created after underground mining. Correspondingly, the filling of the underground goaf area also includes: after each layer of underground mining is mined, waste rock in the open-pit mine is used as aggregate and combined with high-flowability filling material to forcefully fill the goaf area, so that the filling body is in seamless contact with the roof and forms a support strength equivalent to the original ore pillar.

3. The method for combined open-pit and underground mining according to claim 1, characterized in that, Underground mining also includes: Open-pit mining was suspended simultaneously. The process of filling the underground goaf also includes: Open-pit mining operations were carried out simultaneously.

4. The method for coordinated open-pit and underground mining according to claim 3, characterized in that, After the underground goaf is filled, the process also includes: During the curing of the filling layer in the underground goaf, open-pit blasting mining continued.

5. The method for coordinated open-pit and underground mining according to claim 4, characterized in that, The process of returning to open-pit mining operations thereafter, until the mining of the open-pit layer reaches near the level of the underground mining layer and before recovering the isolation layer pillars, also includes: The required safety strength of the backfill is calculated based on the mechanical model, and the safe blasting distance is determined based on the required safety strength. When the horizontal distance between the open-pit mining face and the underground mining face is close to the safe blasting distance, the open-pit mining is suspended, and the open-pit mining work is resumed after the strength of the backfill in the underground mining area reaches the required safety strength.

6. The method for combined open-pit and underground mining according to claim 1, characterized in that, The process of dividing the mining area according to the characteristics of different parts of the ore and specifying the mining plan includes: Based on geological conditions, the ore and rock in open-pit mines are divided into loose ore and rock around the collapse zone, loose ore and rock in the collapse zone, ore and rock outside the collapse zone, and rock mass around the goaf.

7. The method for coordinated open-pit and underground mining according to claim 6, characterized in that, After classifying the ore and rock within the open-pit mine into loosened ore and rock surrounding the subsidence area, unconsolidated ore and rock in the subsidence area, ore and rock on the periphery of the subsidence area, and rock mass surrounding the goaf area based on geological conditions, the following is also included: The loose ore and rock around the collapse area, the loose ore and rock in the collapse area, and the rock mass around the goaf are gradually peeled off layer by layer from top to bottom on a gentle slope. The work proceeds by stripping away the outer ore and rock of the collapsed area from the steep steps down, and the working face advances along the strike of the ore body.

8. The method for combined open-pit and underground mining according to claim 1, characterized in that, The process of dividing the mining area according to the characteristics of different parts of the ore and specifying the mining plan includes: Based on geological conditions, the ore and rock in the open-pit mine are divided into loose ore and rock around the collapse zone, loose ore and rock in the collapse zone, ore and rock outside the collapse zone, and rock mass around the goaf. After arranging the internal transportation system, ventilation and drainage system, and key facilities of the ore body according to environmental constraints and mining process design, it also includes: The caving method is used to recover the pillars in the subsidence area; the top pillar resources within the subsidence area are mainly recovered by large-diameter deep hole capping and segmental recovery, while the intermediate pillars and bottom pillars are mainly recovered by the segmental caving method without bottom pillars, and the ore body is mainly recovered by the staged open field subsequent filling method.

9. The method for combined open-pit and underground mining according to claim 1, characterized in that, The underground mining process also includes: The detonating cord + detonating cord segmented micro-delay blasting and double pre-splitting blasting technology are adopted. In single-row blasting, the middle hole is designed to be detonated first and the side holes are detonated later to control the maximum amount of explosive per blast and strictly limit the impact of blasting on the surrounding area. Transporting the ore body after blasting.

10. A method for coordinated open-pit and underground mining according to claim 9, characterized in that, During the underground mining operation, before transporting the ore body after blasting, the following steps are also included: Dynamic support design is implemented for the roof of the underground mining area based on the blasting disturbance caused by open-pit blasting, in order to avoid overall instability caused by the continuously increasing blasting disturbance.

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